A various types of lithium secondary batteries have been proposed up to now. For example, Patent Literature 1 discloses a non-aqueous electrolyte secondary battery comprising a substance having a peak from 162.9 to 164.0 eV by XPS analysis on the negative electrode surface, wherein, when peak division of the photoelectron spectrum from XPS analysis of the negative electrode surface is performed, the ratio (Cc/Cs) between the carbon concentration Cc (atom %) and the sulfur concentration Cs (atom %) is 5 or more and 50 or less; and the ratio (Cs164/Cs) between the sulfur concentration Cs (atom %) and the concentration Cs164 of the substance having a peak from 162.9 to 164.0 eV (atom %) is 0.001 or more and 0.2 or less; the substance having a peak from 162.9 to 164.0 eV comprises a decomposed substance of a compound represented by the formula (1); and further, an electrolyte comprising a sultone compound represented by the formula (2) at a concentration of 0.005% by mass or more and 10% by mass or less:

wherein Q represents an oxygen atom, methylene group, or a C—S single bond; A represents substituted or unsubstituted alkylene group having 1 to 5 carbon atoms; carbonyl group; sulfinyl group; substituted or unsubstituted fluoroalkylene group having 1 to 6 carbon atoms; or divalent group having 2 to 6 carbon atoms in which a plurality of alkylene units, a plurality of fluoroalkylene units, or an alkylene unit and a fluoroalkylene unit are bonded through an ether bond; and B represents substituted or unsubstituted alkylene group; substituted or unsubstituted fluoroalkylene group; or an oxygen atom;

wherein n represents an integer of 0 or more and 2 or less; and R1 to R6 each independently represent a hydrogen atom, alkyl group having 1 or more and 12 or less carbon atoms, cycloalkyl group having 3 or more and 6 or less carbon atoms, or aryl group having 6 or more and 12 or less carbon atoms.
Patent Literature 2 discloses a non-aqueous secondary battery, wherein the positive electrode consists of a 4-V class active material, and a substance having a peak at 55.0 eV and also a peak at 168.6 eV in XPS analysis exists on the negative electrode surface. The literature states that the peak at 55.0 eV is assigned to a lithium sulfur compound, a peak at 168.6 eV forms a film having a SO2 bond, and the film having a SO2 bond is stable and ion conductive, and has an effect of suppressing decomposition of the electrolyte.
Non Patent Literature 1 suggests a compound comprising an SOx structure as shown in FIG. 1 as a reaction product of 1,3-propanesultone on the carbon negative electrode.